Bump stackprof from 0.2.12 to 0.2.13

Bumps [stackprof](https://github.com/tmm1/stackprof) from 0.2.12 to 0.2.13.
- [Release notes](https://github.com/tmm1/stackprof/releases)
- [Changelog](https://github.com/tmm1/stackprof/blob/master/CHANGELOG.md)
- [Commits](tmm1/stackprof@v0.2.12...v0.2.13)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Gemfile.lock

@@ -345,7 +345,7 @@ GEM
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
-    stackprof (0.2.12)
+    stackprof (0.2.13)
     temple (0.8.1)
     term-ansicolor (1.7.1)
       tins (~> 1.0)